Archery Bow String Suppressor With Adjustable Spring Tension

ABSTRACT

An archery bow string suppression device with adjustable spring tension and isolated free floating transfer rod designed to be used to dampen the shock and vibration normally associated with firing a bow or crossbow.

REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional Application No. 61/188,053 filed on Aug. 6, 2008, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to archery bows, and more specifically to an apparatus that is attached to a compound bow to suppress vibration and sound associated with a bow string when an arrow is released.

2. Description of Related Art

The compound bow is a popular form of bow that allows a user to achieve greater accuracy and distance relative to other types of bows. The compound bow consists of a rigid riser which is the support member for the limbs and a string suppressor. The limbs are very stiff members and a levering system, usually of cables and pulleys are used, to cause the limbs to bend to store all the energy of the bow.

As a user pulls on the bow string, the pull increases to a peak and then “lets off”. This reduced force, or let off, allows a user to more easily hold the bow fully drawn while taking aim. A user will usually use a mechanical release that attaches to the bowstring near the point where the arrow attaches to provide a more consistent release.

The compound bow has a relatively low weight and, therefore, is more sensitive to torque, vibration and slight movements of the users hand and/or arm as an arrow is fired. Torque can occur as the arrow leaves the bow. A problem that can occur with compound bows is the build up of a vibration as an arrow is fired. Normally between 70-85% of the stored energy in the limb members is transferred to the arrow as kinetic energy. Thus, about 15% to 30% of the stored energy is transferred to and absorbed by the limbs and the riser. It is believed that this energy that is transferred to and absorbed by the limbs and the riser is the cause of vibration that occurs in the rigid riser and the stiff limb members.

What is needed is a string suppressor that can be attached to the riser of a compound bow that allows an archer to shoot more accurately by reducing vibration of the bow string when the arrow leaves the bow.

SUMMARY OF THE INVENTION

There is disclosed an archery bow string suppressor adapted to be removably attached to a fitting on an archery bow includes a shaft having a cushion member of vibration damping material mounted on a first end of the shaft for contacting a bow string and dampening string vibrations and a body having a chamber within which the second end of the shaft is located. A mounting bolt having a head surrounded by an O ring is located at one end of the chamber. A spring is also located in the chamber and functions as a shock absorber as the bow string hits the cushion member of said rod.

The foregoing has outlined, rather broadly, the preferred feature of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention and that such other structures do not depart from the spirit and scope of the invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claim, and the accompanying drawings in which similar elements are given similar reference numerals.

FIG. 1 is a side perspective view of a string suppressor with an offset bracket for attachment to the riser of a compound bow in accordance with the principles of the invention;

FIG. 2 is an exploded view of the string suppressor of FIG. 1;

FIG. 3 is a side view of two types of elastomer boots that can be placed on the end of the shaft for contact with the string of a bow;

FIG. 4 is a side perspective view of a string suppressor with a mounting bolt for attachment to the riser of a compound bow in accordance with the principles of the invention; and

FIG. 5 is a partial view of a riser of a compound bow attached to a string suppressor with a mounting bolt in accordance with the principles of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The primary function of the string suppressor disclosed is to reduce string vibration and sound associated with the string when an arrow is being fired from a bow.

The string suppressor has two principle components, a main body and a shaft.

Referring to FIG. 1, there is shown is a side perspective view of a string suppressor 10 which includes a main body 12 and a shaft 14. An offset bracket 16, which is attached to the lower end of the main body 12 allows the shaft to be oriented to be aligned with and engage the string of a bow when an arrow is fired.

Referring to FIG. 2, there is an exploded view of the string suppressor 10 on FIG. 1. The main body 12 and the parts that are located in the main body are shown. The main body is designed with a chamber 18. One end of the chamber supports a thread 20 and the opposite end has an opening 22 within which is a bushing 24 composed of a smooth low friction material such as nylon, Teflon, rubber, Delrin or the like. The shaft 14 is supported by bushing 24 which helps to dampen vibrations by eliminating any metal to metal contact between the shaft and the main body 12, allowing the shaft to move in and out without binding.

The top or string end 26 of the shaft 14 is attached to an elastomer boot 28 and the opposite end of the shaft has threads 30 for receiving two bushings 32, 34. Bushings 32, 34 are composed of Viton or of any other material that can be adjusted along the shaft while also serving to eliminate metal to metal contact.

The bushings are provided for adjusting spring tension, shaft travel and shaft length. The bushings also eliminate metal to metal contact and aid in reducing vibration. Each bushing fits tightly around the threaded end of the shaft and functions as a threaded nut. The bushings can be moved up or down the threaded portion of the shaft by being turned either clock wise or counter clock wise. In place of the threads on the end of the shaft, any type of etching or cross grid on the shaft end can be used which will hold the bushings in place while also allowing a user to adjust their location.

Bushing 34 is provided to control spring tension and shaft travel when an arrow is fired. Bushing 32, which is independent of bushing 34, is used to provide the final adjustment of the shaft length toward the bow string which allows a user to locate the end of the elastomer boot to be spaced slightly away from the bow string while at brace height.

A cap 38, which includes a centrally located threaded mounting bolt 40, is threaded into one end of the main body 12. The opening in cap 38 is sized to provide a slip fit for the threaded shaft 42 of the mounting bolt. The diameter of the head of the mounting bolt is less than the diameter of the cap and is located within an O ring 44. A spring 36, which is in compression, is located between the bushing 34 and cap 38. Thus, one end of spring 36 seats on the bushing 34, which can be of Viton, and the opposite end of the spring seats on O ring 44. The end of spring 36 does not contact the small diameter head of the mounting bolt 40. Spring 36 can be coated with a plastic covering, located within a plastic sleeve or coated with any material or substance which will dampen vibration and allow for a quite and smooth motion of the spring while eliminating any metal to metal contact.

The threaded end 42 of bolt 40 is sized to be threaded into a threaded receiving opening in the riser of a compound bow or into a threaded opening of an off set bracket 16. When an off set bracket is used, the threaded bolt 48 is used to mount the string suppressor to the riser of a compound bow.

In some instances the opening in the riser of the compound bow that is provided for receiving a string suppressor is a smooth bore opening with a set screw, it is not threaded. With bows of this type, cap 38, bolt 40 and off set bracket 16 of FIG. 2 are removed and a second cap 60 has an off center stud, one end of which is threaded into the second cap and the other end is threaded into a rod of metal such as aluminum which has a smooth outside surface. This rod is sized to fit into the smooth bore opening in the riser and is held in position with the set screw. Threading the off center stud on the second cap into the rod allows the string suppressor to be oriented relative to the bow string by rotating the string suppressor about the off center stud.

The outside surface of the main body includes three grooves 25 for receiving O rings. The O rings are provided to allow a user to grip the body 12 when the cap 38 is being unscrewed from the main body 12, or the main body is being attached to or removed from the bow and also serve to absorb vibration resonance from main body 12 before it can be transferred into bow riser.

The shaft, which is provided to transfer energy from the string to a spring located in a chamber in the main body 12, includes a scale 49. The scale is provided to allow a user to see exactly how far the shaft traveled when an arrow is shot. The scale is located where the shaft enters the main body and operates with a floating O ring 50 that is provided to indicate the travel distance of the shaft. To use, a user slides the O ring down the shaft until it touches the top of the main body. When a user shoots an arrow, the string will hit boot 28 pushing in shaft 14 into the main body against the force of spring 36, and then return. As the shaft returns to its rest position, O ring will follow and move with the shaft. The distance between the top of the main body and the O ring is the distance that the shaft traveled.

Referring to FIG. 3 there is shown a side view of two types of elastomer boots 28 that can be placed on the end of the shaft 14 for contact with the string of a bow.

FIG. 4 is a side perspective view of a string suppressor 10 with a standard mounting bolt for attachment to the riser of a compound bow.

FIG. 5 is a partial view of a riser of a compound bow attached to a string suppressor 10 with a mounting bolt.

The string suppressor disclosed differs from other string suppressors in that it uses a spring to dampen string vibration and can be adjusted for tension and travel and isolates rod 14 from direct metal to metal contact from the remaining components of the invention.

The advantages of the string suppressor disclosed are that:

1. The string suppressor has the ability be mounted directly in-line or offset. 2. The string suppressor offers adjustable tension to match a user's individual set-up. 3. The string suppressor offers a smooth and progressive stop opposed to static rod suppressors which abruptly halt the string's forward progress. 4. The string suppressor has adjustable travel 5. The string suppressor has a travel indicator gauge which lets a user know exactly how far the string has moved when an arrow is shot. 6. The string suppressor is not affected by temperature.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiments, it will be understood that various omissions and substitutions and changes of the form and details of the apparatus illustrated and in the operation may be done by those skilled in the art, without departing from the spirit of the invention. 

1. An archery bow string suppressor adapted to be removably attached to a fitting or hole on an archery bow or cross bow, said string suppressor comprising: a shaft having a cushion member of vibration damping material mounted on a first end for contacting a bow string and dampening string vibrations, a body having a chamber within which a second end of said shaft is located; a mounting bolt having a head which may be surrounded by an O ring located at or near one end of said chamber; and a spring located in said chamber having an end which may be seated on an O ring around the head of the mounting bolt and another end resting on an adjustable internal bushing.
 2. The archery bow string suppressor of claim 1 wherein said second end of said shaft is attached to a first bushing and a second bushing located adjacent to said first bushing.
 3. The archery bow string suppressor of claim 2 wherein said first and second bushings are movably attached to shaft, said shaft containing threads, etchings, grooves, or similar items designed to maintain said bushings in their desired location.
 4. The archery bow string suppressor of claim 3 wherein one end of said spring seats on the first bushing.
 5. The archery bow string suppressor of claim 4 wherein said spring may or may not be compressed.
 6. The archery bow string suppressor of claim 5 wherein said first and second bushings are composed of or contained vibration absorbing material such as rubber or elastomer.
 7. The archery bow string suppressor of claim 6 wherein said first bushing controls spring tension and shaft travel.
 8. The archery bow string suppressor of claim 7 wherein said second bushing provides adjustment of the location of the cushion member relative to the bow string when the string suppressor is attached to an archery bow or cross bow.
 9. The archery bow string suppressor of claim 8 wherein a scale is located on said shaft to indicate the distance that the shaft moves when an arrow is shot.
 10. The archery bow string suppressor of claim 9 wherein an O ring or similar type device is moveably coupled to the shaft to mark the distance on the scale that the shaft moves when an arrow is shot.
 11. The archery bow string suppressor of claim 10 wherein said rod is isolated from said body through the use of said first and second bushings as well as additional isolation bushings mounted in said body.
 12. A method of stabilizing a bow string with a string suppressor adapted to be removably attached to a fitting or hole on an archery bow or cross bow, said method comprising: providing a shaft having a cushion member of vibration damping material mounted on a first end for contacting a bow string and dampening string vibrations, providing a body having a chamber within which a second end of said shaft is located; locating a mounting bolt having a head which may be surrounded by an O ring at one end of said chamber; and placing a spring in said chamber with one end seated against the O ring or mounting cap and an opposite end seated against said adjustment bushing.
 13. The archery bow string suppressor of claim 12 wherein second end of said shaft is attached to a first bushing and a second bushing located adjacent to said first bushing.
 14. The method of claim 13 wherein said first and second bushings are movably attached to the shaft.
 15. The method of claim 14 wherein a bushing of vibration absorbing material isolates the body from the shaft.
 16. The method of claim 15 wherein said first and second bushings are composed of or contain vibration absorbing material such as rubber or other elastomers.
 17. The method of claim 16 wherein said first bushing controls spring tension and shaft travel.
 18. The method of claim 17 wherein said second bushing provides adjustment of the location of the cushion member relative to the bow string when the string suppressor is attached to a archery bow or cross bow.
 19. The archery bow string suppressor of claim 18 wherein a scale is located on said shaft and an O ring or similar device is moveably coupled to the shaft to mark a distance on the scale that the shaft moves when an arrow is fired.
 20. The method of claim 13 wherein said second bushing provides final adjustment of the location of the cushion member relative to the bow string when the string suppressor is attached to a bow; and said first bushing sets string tension to control shaft travel when an arrow is shot. 